Method and System for Shaping Partial Fields

The present disclosure relates to photomechanical shaping systems (e.g., Nanoimprint Lithography and Inkjet Adaptive Planarization). In particular, the present disclosure relates to methods of imprinting (also referred to as shaping) full fields, partial fields, and small partial fields on a substrate.

Nano-fabrication includes the fabrication of very small structures that have features on the order of 100 nanometers or smaller. One application in which nano-fabrication has had a sizeable impact is in the fabrication of integrated circuits. The semiconductor processing industry continues to strive for larger production yields while increasing the circuits per unit area formed on a substrate. Improvements in nano-fabrication include providing greater process control and/or improving throughput while also allowing continued reduction of the minimum feature dimensions of the structures formed.

One nano-fabrication technique in use today is commonly referred to as nanoimprint lithography. Nanoimprint lithography is useful in a variety of applications including, for example, fabricating one or more layers of integrated devices by shaping a film on a substrate. Examples of an integrated device include but are not limited to CMOS logic, microprocessors, NAND Flash memory, NOR Flash memory, DRAM memory, MRAM, 3D cross-point memory, Re-RAM, Fe-RAM, STT-RAM, MEMS, and the like. Exemplary nanoimprint lithography systems and processes are described in detail in numerous publications, such as U.S. Pat. Nos. 8,349,241, 8,066,930, and 6,936,194, all of which are hereby incorporated by reference herein.

The nanoimprint lithography technique disclosed in each of the aforementioned patents describes the shaping of a film on a substrate by the formation of a relief pattern in a formable material (polymerizable) layer. The shape of this film may then be used to transfer a pattern corresponding to the relief pattern into and/or onto an underlying substrate.

The shaping process uses a template spaced apart from the substrate. The formable material is applied onto the substrate. The template is brought into contact with the formable material that may have been deposited as a drop pattern using the formable material to spread and fill the space between the template and the substrate. The template may be used to imprint full fields and/or partial fields on the substate. The formable material is solidified to form a film that has a shape (pattern) conforming to a shaping surface of the template. After solidification, the template is separated from the solidified layer such that the template and the substrate are spaced apart.

The substrate and the solidified layer may then be subjected to known steps and processes for device (article) fabrication, including, for example, curing, oxidation, layer formation, deposition, doping, planarization, etching, formable material removal, dicing, bonding, and packaging, and the like. For example, the pattern on the solidified layer may be subjected to an etching process that transfers the pattern into the substrate.

When imprinting full fields, it is advantageous to switch from position control to force control at a predetermined distance from the substrate in order to obtain good filling performance. The same is true for imprinting small fields and small partial fields. However, while all full fields are the same and have the same predetermined distance for switching control, each unique partial field and small partial field should have a distinct predetermined distance for switching the control for good filling performance. Determining the predetermined distance for each unique partial field and small partial field through experimentation is burdensome. Accordingly, there is a need in the art for a method of imprinting partial fields and small partial fields in which determining the location for switching the control does not require burdensome experimentation.

An imprinting method includes moving a template having a shaping surface towards a substrate based on first predetermined position information, upon reaching a first predetermined distance from the substrate, switching from moving the template based on the first predetermined position information to moving the template based on first predetermined force information, contacting the shaping surface with formable material on the substrate such that the total surface area of the shaping surface overlaps the substrate, moving the template towards a substrate based on second predetermined position information, upon reaching a second predetermined distance from the substrate, switching from moving the template based on the second predetermined position information to moving the template based on second predetermined force information, contacting, with the shaping surface, the formable material on the substrate, wherein the shaping surface overlaps an edge of the substrate, wherein the second predetermined distance is equal to the first predetermined distance that is adjusted based on at least one control parameter associated with contacting the formable material with the shaping surface when the shaping surface overlaps the edge of the substrate.

An imprinting method includes moving a template with a shaping surface towards a substrate based on predetermined position information, upon reaching a predetermined distance from the substrate, switching from moving the template based on the predetermined position information to moving the template based on predetermined force information, contacting, with the shaping surface, formable material on the substrate, wherein the shaping surface overlaps an edge of the substrate, wherein the predetermined distance is equal to a reference distance from the substrate that is adjusted based on at least one control parameter associated with contacting the shaping surface with the partial overlap amount, and wherein the reference distance is a distance from the substrate where, in a reference imprinting in which the total surface area of the shaping surface overlaps the substrate, movement of the template switches from being moved based on reference position information to being moved based on reference force information.

A imprinting system includes one or more memory, and one or more processors configured to: move a template having a shaping surface towards a substrate based on first predetermined position information, upon reaching a first predetermined distance from the substrate, switch from moving the template based on the first predetermined position information to moving the template based on first predetermined force information, move the shaping surface with formable material on the substrate such that the total surface area of the shaping surface overlaps the substrate, move the template towards a substrate based on second predetermined position information, upon reaching a second predetermined distance from the substrate, switch from moving the template based on the second predetermined position information to moving the template based on second predetermined force information, contact, with the shaping surface, the formable material on the substrate, wherein the shaping surface overlaps an edge of the substrate, wherein the second predetermined distance is equal to the first predetermined distance that is adjusted based on at least one control parameter associated with contacting the formable material with the shaping surface when the shaping surface overlaps the edge of the substrate.

These and other objects, features, and advantages of the present disclosure will become apparent upon reading the following detailed description of exemplary embodiments of the present disclosure, when taken in conjunction with the appended drawings, and provided claims.

Throughout the figures, the same reference numerals and characters, unless otherwise stated, are used to denote like features, elements, components, or portions of the illustrated embodiments. Moreover, while the subject disclosure will now be described in detail with reference to the figures, it is done so in connection with the illustrative exemplary embodiments. It is intended that changes and modifications can be made to the described exemplary embodiments without departing from the true scope and spirit of the subject disclosure as defined by the appended claims.

The nanoimprint lithography technique can be used in a step and repeat manner to shape a film with a template in a plurality of fields across a substrate. The substrate and a patterning area/shaping surface (mesa) of a template may have different shapes and sizes. For example, the substrate may have a region to be patterned that is circular, elliptical, polygonal, or some other shape. While the mesa is typically smaller than the substrate and has a different shape than the substrate. The substrate is divided into a plurality of full fields and a plurality of partial fields. The full fields are the same size as the mesa. That is the entire surface area of the mesa is equal to the area of a full field. In other words, for a full field, the total surface area of the shaping surface overlaps the substrate. The partial fields are those fields on the edge of the substrate in which the edge of the region to be patterned on the substrate intersects with the patterning area of the mesa. These fields may be divided into multiple categories based on their shape and/or area relative to the full field. For a partial field, only a portion of the surface area of the mesa is equal to the area of the area of a partial field. In other words, for a partial field, the shaping surface overlaps an edge of the substrate.

The partial fields having an area that is less than the an area of a full field area (e.g., the partial field area may be 5% to 99% of the full field area or 10% to 95% of the full field area) tend to have higher defectivity and/or higher processing time than full fields. In addition, small partial fields which may have an area of 50% or less of a full field area or 35% or less than a full field area, are particularly challenging. That is, a small partial field has an area that is equal to 50% or less (or 35% or less) of the area of a full field, which is 50% or less (or 35% or less) of the entire surface area of the mesa. It is desirable to lower defectivity and/or higher processing time for partial fields and small partial fields. The applicant has found that the defectivity and/or higher processing time for small partial fields can be reduced if the initial contact point (ICP) is well chosen. One method of choosing the ICP was described in U.S. Pat. No. 11,614,693.

However, even when a target ICP is well chosen, the applicant has found that, during the imprinting process, it is advantageous to switch from position control to force control at a predetermined distance from the substrate in order to obtain good filling performance. The predetermined distance can be determined through experimentation. However, determining the predetermined distance for each unique partial field and small partial field through experimentation is burdensome. Disclosed herein is a method of imprinting partial fields and small partial fields in which the predetermined distance for switching the control is determined without burdensome experimentation.

1 FIG. 100 100 102 102 104 104 is an illustration of a shaping system(for example a nanoimprint lithography system or inkjet adaptive planarization system) in which an embodiment may be implemented. The shaping systemis used to produce an imprinted (shaped) film on a substrate. The substratemay be coupled to a substrate chuck. The substrate chuckmay be but is not limited to a vacuum chuck, pin-type chuck, groove-type chuck, electrostatic chuck, electromagnetic chuck, and/or the like.

102 104 106 106 106 102 104 104 The substrateand the substrate chuckmay be further supported by a substrate positioning stage. The substrate positioning stagemay provide translational and/or rotational motion along one or more of the positional axes x, y, and z, and rotational axes θ, ψ, and φ. The substrate positioning stage, the substrate, and the substrate chuckmay also be positioned on a base (not shown). The substrate positioning stage may be a part of a positioning system. In an alternative embodiment, the substrate chuckmay be attached to the base.

102 108 108 110 102 108 110 112 108 112 124 112 102 112 108 110 102 110 112 108 102 Spaced-apart from the substrateis a template(also referred to as a superstrate). The templatemay include a body having a mesa (also referred to as a mold)extending towards the substrateon a front side of the template. The mesamay have a shaping surfacethereon also on the front side of the template. The shaping surface, also known as a patterning surface, is the surface of the template that shapes the formable material. The mesa, and more particularly, the shaping surface, has a surface area facing the substrate. In an embodiment, the shaping surfaceis planar and is used to planarize the formable material. Alternatively, the templatemay be formed without the mesa, in which case the surface of the template facing the substrateis equivalent to the mesaand the shaping surfaceis that surface of the templatefacing the substrate.

108 112 114 116 112 102 112 112 The templatemay be formed from such materials including, but not limited to, fused-silica, quartz, silicon, organic polymers, siloxane polymers, borosilicate glass, fluorocarbon polymers, metal, hardened sapphire, and/or the like. The shaping surfacemay have features defined by a plurality of spaced-apart template recessesand/or template protrusions. The shaping surfacedefines a pattern that forms the basis of a pattern to be formed on the substrate. In an alternative embodiment, the shaping surfaceis featureless in which case a planar surface is formed on the substrate. In an alternative embodiment, the shaping surfaceis featureless and the same size as the substrate and a planar surface is formed across the entire substrate.

108 118 118 118 108 108 118 121 121 108 118 The templatemay be coupled to a template chuck. The template chuckmay be, but is not limited to, vacuum chuck, pin-type chuck, groove-type chuck, electrostatic chuck, electromagnetic chuck, and/or other similar chuck types. The template chuckmay be configured to apply stress, pressure, and/or strain to templatethat varies across the template. The template chuckmay include a template magnification control system. The template magnification control systemmay include piezoelectric actuators (or other actuators) which can squeeze and/or stretch different portions of the template. The template chuckmay include a system such as a zone based vacuum chuck, an actuator array, a pressure bladder, etc. which can apply a pressure differential to a back surface of the template causing the template to bend and deform.

118 120 120 120 118 The template chuckmay be coupled to a shaping headwhich is a part of the positioning system. The shaping headmay be moveably coupled to a bridge. The shaping headmay include one or more actuators such as voice coil motors, piezoelectric motors, linear motor, nut and screw motor, etc., which are configured to move the template chuckrelative to the substrate in at least the z-axis direction, and potentially other directions (e.g., positional axes x, and y, and rotational axes θ, ψ, and φ).

100 122 122 122 120 122 120 122 124 102 124 102 124 102 124 102 112 102 124 The shaping systemmay further comprise a fluid dispenser. The fluid dispensermay also be moveably coupled to the bridge. In an embodiment, the fluid dispenserand the shaping headshare one or more or all of the positioning components. In an alternative embodiment, the fluid dispenserand the shaping headmove independently from each other. The fluid dispensermay be used to deposit liquid formable material(e.g., polymerizable material) onto the substratein a drop pattern. Additional formable materialmay also be added to the substrateusing techniques, such as, drop dispense, spin-coating, dip coating, chemical vapor deposition (CVD), physical vapor deposition (PVD), thin film deposition, thick film deposition, and/or the like prior to the formable materialbeing deposited onto the substrate. The formable materialmay be dispensed upon the substratebefore and/or after a desired volume is defined between the shaping surfaceand the substratedepending on design considerations. The formable materialmay comprise a mixture including a monomer as described in U.S. Pat. Nos. 7,157,036 and 8,076,386, both of which are herein incorporated by reference.

122 124 124 Different fluid dispensersmay use different technologies to dispense formable material. When the formable materialis jettable, ink jet type dispensers may be used to dispense the formable material. For example, thermal ink jetting, microelectromechanical systems (MEMS) based ink jetting, valve jet, and piezoelectric ink jetting are common techniques for dispensing jettable liquids.

100 112 126 128 106 108 102 128 126 128 108 124 128 108 124 128 108 124 118 108 124 108 126 124 1 FIG. The shaping systemmay further comprise a curing system that induces a phase change in the liquid formable material into a solid material whose top surface is determined by the shape of the shaping surface. The curing system may include at least a radiation sourcethat directs actinic energy along an exposure path. The shaping head and the substrate positioning stagemay be configured to position the templateand the substratein superimposition with the exposure path. The radiation sourcesends the actinic energy along the exposure pathafter the templatehas contacted the formable material.illustrates the exposure pathwhen the templateis not in contact with the formable material, this is done for illustrative purposes so that the relative position of the individual components can be easily identified. An individual skilled in the art would understand that exposure pathwould not substantially change when the templateis brought into contact with the formable material. In an embodiment, the actinic energy may be directed through both the template chuckand the templateinto the formable materialunder the template. In an embodiment, the actinic energy produced by the radiation sourceis UV light that induces polymerization of monomers in the formable material.

100 136 124 108 124 100 136 108 136 136 108 108 124 136 136 124 108 108 136 124 112 130 1 FIG. 1 FIG. 1 FIG. The shaping systemmay further comprise a field camerathat is positioned to view the spread of formable materialafter the templatehas contacted the formable material.illustrates an optical axis of the field camera's imaging field as a dashed line. As illustrated inthe shaping systemmay include one or more optical components (dichroic mirrors, beam combiners, prisms, lenses, mirrors, etc.) which combine the actinic radiation with light to be detected by the field camera. The field cameramay be configured to detect the spread of formable material under the template. The optical axis of the field cameraas illustrated inis straight but may be bent by one or more optical components. The field cameramay include one or more of: a CCD; a sensor array; a line camera; and a photodetector which are configured to gather light that has a wavelength that shows a contrast between regions underneath the templatethat are in contact with the formable material, and regions underneath the templatewhich are not in contact with the formable material. The field cameramay be configured to gather monochromatic images of visible light. The field cameramay be configured to provide images of the spread of formable materialunderneath the template; the separation of the templatefrom cured formable material; and can be used to keep track of the imprinting (shaping) process. The field cameramay also be configured to measure interference fringes, which change as the formable material spreadsbetween the gap between the shaping surfaceand the substrate surface.

100 138 136 138 138 138 112 124 102 136 138 112 124 The shaping systemmay further comprise a droplet inspection systemthat is separate from the field camera. The droplet inspection systemmay include one or more of a CCD, a camera, a line camera, and a photodetector. The droplet inspection systemmay include one or more optical components such as lenses, mirrors, optical diaphragms, apertures, filters, prisms, polarizers, windows, adaptive optics, and/or light sources. The droplet inspection systemmay be positioned to inspect droplets prior to the shaping surfacecontacting the formable materialon the substrate. In an alternative embodiment, the field cameramay be configured as a droplet inspection systemand used prior to the shaping surfacecontacting the formable material.

100 134 108 102 134 102 108 124 134 100 136 108 124 102 134 108 124 108 124 108 124 108 102 134 102 1 FIG. 1 FIG. 1 FIG. The shaping systemmay further include a thermal radiation sourcewhich may be configured to provide a spatial distribution of thermal radiation to one or both of the templateand the substrate. The thermal radiation sourcemay include one or more sources of thermal electromagnetic radiation that will heat up one or both of the substrateand the templateand does not cause the formable materialto solidify. The thermal radiation sourcemay include a SLM such as a digital micromirror device (DMD), Liquid Crystal on Silicon (LCoS), Liquid Crystal Device (LCD), etc., to modulate the spatio-temporal distribution of thermal radiation. The shaping systemmay further comprise one or more optical components which are used to combine the actinic radiation, the thermal radiation, and the radiation gathered by the field cameraonto a single optical path that intersects with the imprint field when the templatecomes into contact with the formable materialon the substrate. The thermal radiation sourcemay send the thermal radiation along a thermal radiation path (which inis illustrated as 2 thick dark lines) after the templatehas contacted the formable material.illustrates the thermal radiation path when the templateis not in contact with the formable material, this is done for illustrative purposes so that the relative position of the individual components can be easily identified. An individual skilled in the art would understand that the thermal radiation path would not substantially change when the templateis brought into contact with the formable material. Inthe thermal radiation path is shown terminating at the template, but it may also terminate at the substrate. In an alternative embodiment, the thermal radiation sourceis underneath the substrate, and thermal radiation path is not combined with the actinic radiation and the visible light.

124 132 102 132 132 102 104 132 102 102 104 132 102 102 Prior to the formable materialbeing dispensed onto the substrate, a substrate coatingmay be applied to the substrate. In an embodiment, the substrate coatingmay be an adhesion layer. In an embodiment, the substrate coatingmay be applied to the substrateprior to the substrate being loaded onto the substrate chuck. In an alternative embodiment, the substrate coatingmay be applied to substratewhile the substrateis on the substrate chuck. In an embodiment, the substrate coatingmay be applied by spin coating, dip coating, drop dispense, slot dispense, etc. In an embodiment, the substratemay be a semiconductor wafer, a glass wafer, a sapphire wafer, or some other material. In another embodiment, the substratemay be a blank template (replica blank) that may be used to create a daughter template after being imprinted.

100 102 102 108 108 108 108 The shaping systemmay include an imprint field atmosphere control system such as gas and/or vacuum system, an example of which is described in U.S. Patent Publication No. 2010/0096764 and U.S. Pat. No. 10,895,806 which are hereby incorporated by reference. The gas and/or vacuum system may include one or more of pumps, valves, solenoids, gas sources, gas tubing, etc. which are configured to cause one or more different gases to flow at different times and different regions. The gas and/or vacuum system may be connected to a first gas transport system that transports gas to and from the edge of the substrateand controls the imprint field atmosphere by controlling the flow of gas at the edge of the substrate. The gas and/or vacuum system may be connected to a second gas transport system that transports gas to and from the edge of the templateand controls the imprint field atmosphere by controlling the flow of gas at the edge of the template. The gas and/or vacuum system may be connected to a third gas transport system that transports gas to and from the top of the templateand controls the imprint field atmosphere by controlling the flow of gas through the template. One or more of the first, second, and third gas transport systems may be used in combination or separately to control the flow of gas in and around the imprint field.

100 140 104 106 118 120 122 126 134 136 138 140 142 140 140 140 100 100 140 140 141 140 140 a a a a The shaping systemmay be regulated, controlled, and/or directed by one or more processors(controller) in communication with one or more components and/or subsystems such as the substrate chuck, the substrate positioning stage, the template chuck, the shaping head, the fluid dispenser, the radiation source, the thermal radiation source, the field camera, imprint field atmosphere control system, and/or the droplet inspection system. The processormay operate based on instructions in a computer readable program stored in a non-transitory computer readable memory. The processormay be or include one or more of a CPU, MPU, GPU, ASIC, FPGA, DSP, and a general-purpose computer. The processormay be a purpose-built controller or may be a general-purpose computing device that is adapted to be a controller. Examples of a non-transitory computer readable memory include but are not limited to RAM, ROM, CD, DVD, Blu-Ray, hard drive, networked attached storage (NAS), an intranet connected non-transitory computer readable storage device, and an internet connected non-transitory computer readable storage device. The controllermay include a plurality of processors that are both included in the shaping systemand in communication with the shaping system. The processormay be in communication with a networked computeron which analysis is performed and control files such as a drop pattern are generated. In an embodiment, there are one or more graphical user interface (GUI)on one or both of the networked computerand a display in communication with the processorwhich are presented to an operator and/or user.

120 106 110 102 124 120 108 110 124 124 126 124 130 112 102 124 108 124 102 100 112 100 112 Either the shaping head, the substrate positioning stage, or both varies a distance between the moldand the substrateto define a desired space (a bounded physical extent in three dimensions) that is filled with the formable material. For example, the shaping headmay apply a force to the templatesuch that moldis in contact with the formable material. After the desired volume is filled with the formable material, the radiation sourceproduces actinic radiation (e.g., UV, 248 nm, 280 nm, 350 nm, 365 nm, 395 nm, 400 nm, 405 nm, 435 nm, etc.) causing formable materialto cure, solidify, and/or cross-link; conforming to a shape of the substrate surfaceand the shaping surface, defining a patterned layer on the substrate. The formable materialis cured while the templateis in contact with formable material, forming the patterned layer on the substrate. Thus, the shaping systemuses a shaping process to form the patterned layer which has recesses and protrusions which are an inverse of the pattern in the shaping surface. In an alternative embodiment, the shaping systemuses a shaping process to form a planar layer with a featureless shaping surface.

130 110 110 110 112 102 110 102 102 102 110 102 The shaping process may be done repeatedly in a plurality of imprint fields (also known as just fields or shots) that are spread across the substrate surface. Each of the full field imprint fields may be the same size as the mesaor just the pattern area of the mesa. The pattern area of the mesais a region of the shaping surfacewhich is used to imprint (shape) patterns on a substratewhich are features of the device or are then used in subsequent processes to form features of the device. The pattern area of the mesamay or may not include mass velocity variation features (fluid control features) which are used to prevent extrusions from forming on imprint field edges. In an alternative embodiment, the substratehas only one imprint field (shaping field) which is the same size as the substrateor the area of the substratewhich is to be patterned with the mesa. In an alternative embodiment, the imprint fields overlap. As noted above, some of the imprint fields may be partial imprint fields or small partial imprint fields which intersect with a boundary of the substrate.

124 130 112 114 110 The patterned layer may be formed such that it has a residual layer having a residual layer thickness (RLT) that is a minimum thickness of formable materialbetween the substrate surfaceand the shaping surfacein each imprint field. The patterned layer may also include one or more features such as protrusions which extend above the residual layer having a thickness. These protrusions match the recessesin the mesa.

2 FIG.A 2 FIG.A 2 FIG.B 2 FIG.B 2 FIGS.A-B 108 112 110 110 244 110 246 244 112 110 246 110 246 246 108 210 246 244 110 108 108 108 e is an illustration of a template(not to scale) that may be used in an embodiment. The shaping surfacemay be on a mesa(identified by the dashed box in). The mesais surrounded by a recessed surfaceon the front side of the template. The mesahas a mesa height hr. The mesa height hr may between 1-200 μm. Mesa sidewallsconnect the recessed surfaceto shaping surfaceof the mesa. The mesa sidewallssurround the mesa. In an embodiment in which the mesa is round or has rounded corners, the mesa sidewallsrefers to a single mesa sidewall that is a continuous wall without corners. In an embodiment, the mesa sidewallsmay have one or more of a perpendicular profile; an angled profile; a curved profile; a staircase profile; a sigmoid profile; a convex profile; or a profile that is combination of those profiles.is a perspective view of the template(not to scale) showing the mesa edges.illustrates that the intersection of the mesa sidewallsand the recessed surfacemay have some curvature due to the process of etching away material form a template precursor to form the mesaon the template. The templatemay have a square planar shape with a template width WT as illustrated in. In an alternative embodiment, the template width WT is a characteristic width and a planar shape of the templatemay be a rectangle, parallelogram, polygon, or circle, or some other shape. The template width WT may be between 10-450 mm.

3 FIG. 300 100 300 124 300 102 100 140 300 is a flowchart of a method of manufacturing an article (device) that includes a shaping processperformed by the shaping system. The shaping processcan be used to form patterns in formable materialon one or more imprint fields (also referred to as: pattern areas or shot areas). The shaping processmay be performed repeatedly on a plurality of substratesby the shaping system. The processormay be used to control the shaping process.

300 102 112 102 In an alternative embodiment, the shaping processis used to planarize the substrate. In which case, the shaping surfaceis featureless and may also be the same size or larger than the substrate.

300 108 118 300 140 102 104 108 102 100 108 102 The beginning of the shaping processmay include a template mounting step causing a template conveyance mechanism to mount a templateonto the template chuck. The shaping processmay also include a substrate mounting step, the processormay cause a substrate conveyance mechanism to mount the substrateonto the substrate chuck. The substrate may have one or more coatings and/or structures. The order in which the templateand the substrateare mounted onto the shaping systemis not particularly limited, and the templateand the substratemay be mounted sequentially or simultaneously.

140 106 102 122 102 302 140 122 122 124 122 122 124 122 124 302 + d In a positioning step, the processormay cause one or both of the substrate positioning stageand/or a dispenser positioning stage to move an imprinting field i (index i may be initially set to 1) of the substrateto a fluid dispense position below the fluid dispenser. The substrate, may be divided into N imprinting fields, wherein each imprinting field is identified by a shaping field index i. In which N is the number of shaping fields and is a real positive integer such as 1, 10, 62, 75, 84, 100, etc. {N∈}. In a dispensing step S, the processormay cause the fluid dispenserto dispense formable material based on a drop pattern onto an imprinting field. In an embodiment, the fluid dispenserdispenses the formable materialas a plurality of droplets. The fluid dispensermay include one nozzle or multiple nozzles. The fluid dispensermay eject formable materialfrom the one or more nozzles simultaneously. The imprint field may be moved relative to the fluid dispenserwhile the fluid dispenser is ejecting formable material. Thus, the time at which some of the droplets land on the substrate may vary across the imprint field i. The dispensing step Smay be performed during a dispensing period Tfor each imprint field i.

302 124 102 In an embodiment, during the dispensing step S, the formable materialis dispensed onto the substratein accordance with a drop pattern. The drop pattern may include information such as one or more of position to deposit drops of formable material, the volume of the drops of formable material, type of formable material, shape parameters of the drops of formable material, etc. In an embodiment, the drop pattern may include only the volumes of the drops to be dispensed and the location of where to deposit the droplets.

304 140 106 112 108 124 304 112 124 118 108 112 108 118 112 130 136 136 112 130 112 contact d contact contact After, the droplets are dispensed, then a contacting step Smay be initiated, the processormay cause one or both of the substrate positioning stageand a template positioning stage to bring the shaping surfaceof the templateinto contact with the formable materialin a particular imprint field. The contacting step Smay be performed during a contacting period Twhich starts after the dispensing period Tand begins with the initial contact of the shaping surfacewith the formable material. As discussed in more detail below, prior to the contact period, control of the movement of the template chuck may switch from a position control method to force control method. In an embodiment, by the beginning of the contact period Tthe template chuckis configured to bow out the templateso that only a portion of the shaping surfaceis in contact with a portion of the formable material. In an embodiment, the contact period Tends when the templateis no longer bowed out by the template chuck. The degree to which the shaping surfaceis bowed out relative to the substrate surfacemay be estimated with the spread camera. The spread cameramay be configured to record interference fringes due to reflectance from at least the shaping surfaceand the substrate surface. The greater the distance between neighboring interference fringes, the larger the degree to which the shaping surfaceis bowed out.

306 124 246 246 124 136 306 304 100 f f f C f During a filling step S, the formable materialspreads out towards the edge of the imprint field and the mesa sidewalls. The edge of the imprint field may be defined by the mesa sidewalls. How the formable materialspreads and fills the mesa may be observed via the field cameraand may be used to track a progress of a fluid front of formable material. In an embodiment, the filling step Soccurs during a filling period T. The filling period Tbegins when the contacting step Sends. The filling period Tends with the start of a curing period T. In an embodiment, during the filling period Tthe back pressure and the force applied to the template are held substantially constant. Substantially constant in the present context means that the back pressure variation and the force variation is within the control tolerances of the shaping systemwhich may be less 0.1% of the set point values.

308 140 126 108 110 112 124 112 124 C C C In a curing step S, the processormay send instructions to the radiation sourceto send a curing illumination pattern of actinic radiation through the template, the mesa, and the shaping surfaceduring a curing period T. The curing illumination pattern provides enough energy to cure (polymerize) the formable materialunder the shaping surface. The curing period Tis a period in which the formable material under the template receives actinic radiation with an intensity that is high enough to solidify (cure) the formable material. In an alternative embodiment, the formable materialis exposed to a gelling illumination pattern of actinic radiation before the curing period Twhich does not cure the formable material but does increase the viscosity of the formable material.

310 140 104 106 118 120 112 108 102 302 302 124 302 304 S In a separation step S, the processoruses one or more of: the substrate chuck; the substrate positioning stage, template chuck, and the shaping headto separate the shaping surfaceof the templatefrom the cured formable material on the substrateduring a separation period T. If there are additional imprint fields to be imprinted, then the process moves back to step S. In an alternative embodiment, during step Stwo or more imprint fields receive formable materialand the process moves back to steps Sor S.

300 102 312 In an embodiment, after the shaping processis finished additional semiconductor manufacturing processing is performed on the substratein a processing step Sso as to create an article of manufacture (e.g., semiconductor device). In an embodiment, each imprint field includes a plurality of devices.

312 312 102 The further semiconductor manufacturing processing in processing step Smay include etching processes to transfer a relief image into the substrate that corresponds to the pattern in the patterned layer or an inverse of that pattern. The further processing in processing step Smay also include known steps and processes for article fabrication, including, for example, inspection, curing, oxidation, layer formation, deposition, doping, planarization, etching, formable material removal, dicing, bonding, packaging, mounting, circuit board assembly, and the like. The substratemay be processed to produce a plurality of articles (devices).

300 108 102 102 110 108 102 110 102 102 102 110 110 110 110 110 4 FIGS.A-B The shaping processcan be used in a step and repeat manner to shape a film with a templatein a plurality of fields across the substrate. The substrateand a patterning area (mesa) of a templatemay have different shapes and sizes. For example, the substratemay have a region to be patterned that is circular, elliptical, polygonal, or some other shape. The mesais typically smaller than the substrateand has a different shape then the substrate. The substrateis divided into a plurality of full fields and a plurality of partial fields/small partial fields as illustrated in. As discussed above, the full fields are the same size as the mesaor patterning area (shaping surface) of the mesa. That is, the entire surface area of the mesais equal to the area of one full field such that the total surface area of the shaping surface overlaps the substrate. The partial fields and small partial fields are those fields on the edge of the substrate in which the edge of the region to be patterned on the substrate intersects with the patterning area of the mesa (shaping surface), such that the shaping surface overlaps an edge of the substrate. As noted above, a partial field is a field whose area is less than the area of a full field, which is also less than the entire surface area (shaping surface) of the mesa. These fields may be divided into multiple categories based on their shape and/or area relative to the full field. A subset of those partial fields maybe categorized as small partial fields. A partial field may be defined as having a surface area that is less than an entire surface area of the mesa, may be defined as having a surface area that is 5% to 99% of the entire surface area of the mesa, or may be defined as having a surface area that is 10% to 95% of the entire surface area of the mesa. A small partial field may be defined as having a surface area that is equal to 50% or less (or 35% or less) of the area of a full field, which is also 50% or less (or 35% or less) of the entire surface area of the mesa.

4 FIG.C 4 FIG.C 4 FIG.C 4 FIG.C 448 102 110 210 110 450 450 102 102 102 e i,m is an illustration of a particular small partial fieldon a substratein the coordinate system of the mesa. Inthe mesa edgesare illustrated as dotted lines.also shows the mesa origin Oof the coordinate system of the mesa which is at the center of the mesa. A patternable area edgeis shown inset from the substrate edge. In an embodiment, the patternable area edgemay be inset from the substrate edge by between 0 to 3 mm. The non-patterned area is illustrated with a diamond gird pattern in. The width of the non-patterned area may be determined by an edge treatment of the substratewhich may have been treated to have rounded, beveled, or chamfered edges. The substratemay also have undergone numerous previous processes which cause the edge to have a random unpredictable pattern. The substratemay also have an orientation feature such as a notch or a flat edge.

4 FIG.C 448 210 448 450 450 450 450 210 e e As illustrated inthe extent of the particular small partial fieldis defined on two sides by the mesa edgewhich intersect at a vertex B. The extent of the small partial fieldis also defined by the arc of the patternable area edge. The arc of the patternable area edgemay be defined as a portion of a circle, an ellipse, a spline, a polygon, or other geometric quantity that can be used to define a shape of the patternable area edge. The arc of the patternable area edgeintersects the mesa edgesat vertices A and C. This is an exemplary small partial field. The small partial field may have other shapes, which have at least on curved edge and 1 or more straight edges.

300 302 108 124 102 108 118 108 124 304 i i,θ i,r s i i,m i,m The shaping processis controlled using numerous parameters. In an embodiment, one of the process parameters used during the contacting step Sis the target initial contact point (ICP) for each field i (ICP={ICP, ICP}). In an embodiment, polar coordinates relative to the substrate center (O) may be used to describe target ICP. The location of the target ICPmay also be described as angle θrelative to center of the mesa O. In an alternative embodiment, another coordinate system may be used. The target ICP is the point in the field in which the templateis brought into initial contact with formable materialon the substrate. The templateis bowed out by the template chuckso that only a small portion of the templateis brought into contact with the formable materialat the target ICP. The bowing of the template is reduced as the template is brought closer to the substrate, until the template is flat, this is done to allow gas to escape during the contacting step Sand to ensure that the formable material spreads in a controlled manner.

i,m s 2 136 For full fields, the target ICP is at the center of the full field the mesa O. While the target ICP is a single point, the actual initial contact area is a larger area which may have an area of for example of 1 to 20 mmwhich can be determined by around the time when interference fringes first start to show up in images obtained by the field camera. For partial fields, determining the target ICP is more complicated which depends on the shape and area of the partial field and the location of the partial field relative to the center of the substrate (O). For certain partial fields (e.g., those having an area that is 50% to less than 100% of the area of a full field) the target ICP may be at the same point as the full field or somewhere within the initial contact area. For other partial fields (e.g., those having an area that is 25%-50% of the area of a full field), the target ICP may be determined by calculating a geometric center (GC) or a centroid of the partial field. There are several methods that may be used for determining the GC. One method of estimating the GC is to use a method of intersecting meridians. Another method is to approximate the edge of the partial field using a function. The function may be defined in a piecewise manner and be continuous over the partial field. Integration may then be used to estimate a geometric center of the partial field. A third method of identifying the GC is to minimize distances from the GC to the farthest corners of the partial field.

448 The GC does not work as well for small partial fields. One method of determining a target ICP for small partial fields is described in US Patent Publication No. 2023-0014261 which is hereby incorporated by reference. As noted above, in an embodiment a partial field may be categorized as a small partial fieldif it has an area that is less than a fractional area threshold for example 50% of the area of a full field or 35% of the area of a full field. For an alternative embodiment, the fractional area threshold may have a different value for example one of: 1%; 5%; 10%; 15%; 20%; 25%; 30%; 45%; 50% etc. In an embodiment, the target ICP is not the GC for small partial fields and the target ICP is coincident with the center of the mesa or could alternatively be the GC for partial fields that are not categorized as small partial fields.

4 FIGS.A-B 4 FIG.D 4 FIG.D 4 FIG.D i i i,A i,θ i i,A i,θ i i,r i,θ i,θ i,θ As illustrated indifferent layouts of imprint fields results in different sizes and shapes of partial fields. The partial fields can have complex shapes with 1 to 4 four straight edges and 1 curved edge that meet at 2-5 vertexes for the example where the mesa is a quadrangle, and the substrate is a circle. When determining ICP control values for a partial field it is necessary to know the shape of the partial field. The traditional method of describing the shape of a partial field is to identify positions of all of the vertexes of the shape and the shape of lines connecting all these vertexes. Another method of describing a partial field is as the intersection of two shapes in which the size, shape, and relative positions of these shapes are listed. While this would provide a complete description of the partial field it is not necessary for purposes of determining ICP control values. A partial field shape description Ffor a partial field i can be simplified to just two or three values. For example, a partial field shape description set Fmay include: the area of the partial field shape relative to the area of a full field (F); and an azimuthal angle that represents the angle in the plane of the substrate of a center of the mesa relative to the middle of the substrate (F) (F={F, F}) as illustrated in. Also illustrated inin the target ICP for the imprint field i (ICP={ICP, ICP}). As illustrated inthe azimuthal coordinate of the imprint field i (ICP) is different than the azimuthal coordinate of the partial field shape description (F) although in some circumstances they may be the same.

300 304 304 140 108 124 102 108 102 448 i i T T Sa Sb Sc S T j j,T j,Sa j,Sb j,Sc j,T j,A j,θ j A method for determining ICP control values is disclosed in U.S. patent application Ser. No. 18/127,074, filed Mar. 28, 2023 (hereinafter, “the '074 application”), which is incorporated by reference herein it its entirety. In particular, the section of the '074 application titled “Method of Determining ICP control values” is the most relevant portion. The shaping processincludes a contacting step S. As noted in the '074 application, the contacting step Sincludes receiving a set of contact control values Vfor a partial field i from a processor. The set of contact control values Vmay include: a template cavity pressure Papplied to a portion of a template during initial contact of the templatewith formable materialon a substratewhich causes the templateto be curved with radius of curvature of the template R; a set of substrate pressures (P, P, and P) applied to a portion of the substrate during initial contact of the template with formable material on the substrate which causes the substratein the partial field to be curved with a radius of curvature R; and a tilt (θ) of the template relative to the substrate during initial contact of the template with formable material on the substrate. The '074 application provides a flowchart of an ICP control value determination process for small partial fields. By implementing the method described in the '074 application, a set of calibration data Cassociated with a specific imprint process j including the following data may be established: the tilt of the template tilt (θ); one or more substrate pressure control values (P, P, and P); template cavity pressure (P); area of the partial field (F); and azimuthal angle of the partial field (F). As noted in the '074 application, the superset of calibration data C may include 10s; 100s or 1000s of sets of calibration Data C.

i i,D i i i i,T i,Sa i,Sb i,Sc i,T 108 124 304 As explained in the '074 application, the ICP control value determination process may include a control condition determination step in which the set of contact control values Vwhich allow the templateto initially contact the formable materialat the ICPare determined based on the partial field description F, and the superset of calibration data. The control condition determination step may output a set of contact control values Vwhich may then be used in a step Sto imprint partial field i. The set of contact control values Vmay include: a template cavity pressure P; a set of substrate pressures (P, P, and P); and a template tilt (θ).

i i,T T T 118 108 108 108 118 108 108 112 108 112 112 112 5 FIG.A 5 FIG.B As discussed in the '074 application, the set of contact control values Vfor an imprint field i may include a template back pressure (P) that is applied by the template chuckto a back surface of the template which bows out the templatewhen imprinting partial field i.is an illustration of a pump connected to an exemplary template chuckfor holding a templatedetails of which are described in US Patent Publication No. 2017/0165898 which is hereby incorporated by reference in its entirety. The template chuckmay include one or more vacuum portions which hold the templateand a chamber portion which can be used to bow out templateas illustrated inwhen it is contacting a full field i. By increasing the pressure in the chamber above the ambient pressure of the shaping surface, the templateis bowed out causing the shaping surfaceto have a curvature that may be approximated by a radius of curvature of the template (R) at the ICP. The radius of curvature of the template Ris an approximate representative of a shape of the shaping surfaceat the ICP. A polynomial (for example a fourth order polynomial) may also be used to approximate the shape of the shaping surfacein the region of the ICP at the time of initial contact. A finite element model or other simulation model may be used to determine a shape of the shaping surface under different control conditions.

Tx Ty i,T i,Tx i,Ty Tx Ty i,Tx i,Ty i 5 FIG.C 5 FIG.C 120 108 102 112 102 102 112 The control conditions may include a tipping angle of the template (θrotation of the template about the x-axis) and a tilting angle of the template (θrotation of the template about the y-axis), which together are the template control angles (θ={θ, θ}) relative to the substrate as illustrated inwhen imprinting a full field i. In an embodiment, θmay be a function G of θand one or both components of the partial field description F of the imprint field i (θ=G(θ, F)). In which case only one component of the template control angles needs to be known. The function G may be determined experimentally or through simulation such that certain conditions are maintained. The imprint headmay include a plurality of actuators that are used to position the templaterelative to the substratethese plurality of actuators can also be used to tilt the shaping surfacerelative to the substrate.shows the tilt of a reference surface (front surface of the template chuck) relative to the substratewhich is at the same angle as shaping surfacewhen it is not bowed out.

104 104 102 104 504 504 504 104 504 504 504 130 112 5 FIG.D a b c b a c S The control conditions may include a set of substrate chuck control values supplied to the substrate chuck. The substrate chuckmay deform a shape of the substrate. As illustrated in, the substrate chuckmay be a zone chuck in which different zones (for example outer zone, first inner zone, second inner zone, etc.) may be supplied with different amounts of positive or negative pressure which causes the substrate to be deformed by between 1-10 μm. The substrate chuckhas at least 2 zones but may have 3, 4, 5, 6, 7, 8, 9, 10, or more zones. For example, positive pressure may be supplied to the first inner zonewhile negative pressures are supplied to the outer zoneand the second inner zone. As with the template the shape of the substrate surfacemay be approximately represented by a radius of curvature of the substrate (R) at the ICP. A polynomial (for example a fourth order polynomial) may also be used to approximate the shape of the shaping surfacein the region of the ICP at the time of initial contact. A finite element model or other simulation model may be used to determine a shape of the shaping surface under different control conditions.

T T Sa Sb Sc S Tx Ty T i,A i,θ 448 112 130 112 130 5 FIG.E The control conditions (a template cavity pressure Pfor controlling the radius of curvature of the template R; substrate pressures P, P, and Pfor controlling the radius of curvature of the substrate R; template tilts θand θ; etc.) may be adjusted in combination or independently to control where the ICP is on the small partial fieldas illustrated in. The control conditions may include additional parameters which describe the shapes and orientations of the shaping surfaceat ICP and the substrate surfaceat ICP. The control parameters may include a plurality of control values and/or trajectories (pressures, currents, voltages, binary control signals, etc.) which are used to determine the shapes and orientations of the shaping surfaceat ICP and the substrate surfaceat ICP. The applicant has found that there are typically multiple different solutions to the selection of control conditions to achieve a specific ICP. The selection of which of these solutions is appropriate may depend upon the small partial field size, overlay constraints, alignment constraints, defectivity, process time, etc. This will also have an impact on which control conditions are adjusted as explained in the '074 application. As explained in the '074 application, the adjusting control conditions may be performed by adjusting template cavity pressure Pwhile keeping the other control conditions at default setting(s) depending on the partial field area Fand/or the azimuthal angle of the partial field (F).

T S i,Tx i,Ty i,Tx i,Ty i,Tx i,Ty 306 306 108 102 100 244 130 112 112 130 The amount of pressure that is supplied to the chamber depends on the desired radius of curvatures (R, R) at ICP and during the filling step Swhich may be determined based on reducing non-fill defects caused by gas not escaping during the filling step Sfor a given fill time. There are control limitations on the control parameters based on the mechanical characteristics of the template, the substrate, and the shaping system. These limitations prevent: the recessed surfaceof the template from contacting the substrate surfaceor an applique surrounding the substrate; and/or the shaping surfacefrom contacting the applique surrounding the substrate. In an alternative embodiment, the ICP is chosen within the ICP range based on limitations on the control parameters. These limitations may be determined experimentally, and/or using a finite element model or other simulation methods. For example, when both the template and substrate are flat the template angle can be calculated using trigonometry as described in equation (1) below. Once the shape of a bowed out shaping surfaceand/or shape of bowed out substrate surfaceare determined coordinate transformations may be used to determine the limitations. The relationship between θand θis also described in equation (1) below for an ideal value for θand θ. The applicant has found that an ideal solution is not always effective and other values for θand θmust be determined through simulation and experimentation.

Generating the Superset of Calibration Data

j j j j j j j j 5 FIG.F As discussed in the '074 application each individual element of the superset of calibration data Cshould include: control values V; a partial field description F; and the initial contact point ICP. Each set of calibration data Cmay be determined via experimentation. In which a series of experiments are performed at a series of different partial fields as illustrated in. For each partial field j with a specific partial field description (F) multiple experiments are performed with different sets of control values Vthat each produce a different ICP. Examples of such experiments are described in the '074 application.

Shaping Method with Switching Control Type

600 650 600 650 6 FIG.A 6 FIG.B 6 FIG.A 6 FIG.B When imprinting a full field (and also when imprinting partial fields and small partial field discussed below), there are two control phases. The first control phase is referred herein as “position control.” The second control phase is referred herein as “force control.” Position control, as used herein, means that movement of the template chuck is controlled using a feedback loop that is based on measured position information of the template chuck and is not based on any information about force imparted onto the template chuck. Force control, as used herein, means that the movement of the template chuck is controlled using a feedback loop that is based on both measured position information of the temple chuck and on information about the estimated residual force imparted onto the template chuck. An example of a method of position controlis illustrated in the flowchart of. An example of a method of force controlis illustrated in the flowchart of. The position control methodis the same no matter what field is being printed (i.e., full, partial, small partial, etc.). Likewise, the force control methodis the same no matter what field is being printed (i.e., full, partial, small partial, etc.). Thus, the position control ofand the force control ofare applicable to any size field being imprinted.

600 602 112 130 602 118 118 102 600 118 602 i,Tx i,Ty i,Tx i,Ty k k 6 FIG.A The position control methodmay begin with step Swhere the measured position of the template chuck is measured. The measured position of, for example, a top surface of the template chuck may be measured with three or more position encoders that measure the position of the template chuck relative to a resting plane. The actual position of the template chuck may include: a z-position along a z-axis; a rotation around an x-axis (θ); and a rotation around a y-axis (θ). The actual position of the template chuck may include three separate z-positions along three different z-axes. The actual position of the template chuck may be adjusted based on the imprint field i and measured height variation of the substrate chuck and/or substrate such that it is representative of a gap between the shaping surfaceof a reference template swelled with a reference pressure and the substrate surface. The template chuck is an extended object and the position (including rotations) of the template chuck means the position of one or more reference points on the template chuck. If the reference point(s) are changed then calibration data will change accordingly. The reference point(s) may be based on the encoders used to measure the position of the template chuck. At the start of the method in stepit is presumed that the template chuck has already begun to move toward the substrate from a resting plane according to a predetermined position trajectory. The predetermined position trajectory is data indicating the desired position of the template chuck at a particular time during the shaping process. The predetermined position trajectory is the relative z position along the z-axis and may also include rotation around the x-axis (θ), and a rotation around the y-axis (θ) relative to a reference plane. The predetermined position trajectory may be a relative time series of data points, a smooth function of relative time, a piecewise smooth function of relative time. The predetermined position trajectory may be a differentiable function that is differentiable with respect to time over a time period in which the predetermined position trajectory is used. The predetermined position trajectory may be a twice differentiable function that is twice differentiable with respect to time over a time period in which the predetermined position trajectory is used. Relative time in the present context is time relative to an initial starting time that depends on when the template chuck leaves the resting plane. The resting plane may be a fixed location above the substrate chuck at which the template chuck rests in between imprinting when imprinting multiple fields on the substrate. The resting plane may be a neutral plane where the template chuck rests when no force is supplied by the actuators. The template chuckmay be connected to one or more springs and/or flexures that supply a resisting force that prevents the template from contacting the substrate unless the actuators supply a force. As the template chuckbegins to move toward the substratefollowing the predetermined position trajectory, the position control methodfeedback loop is implemented. Thus, the actual position of the template chuckmeasured in step Sis done at a particular time t. The index k is a time index which represents a short time period in which measurements and actions are taken by the controller during the imprinting of a single field. In other words, each time the method ofis performed the actual position of the template chuck is measured for a particular time t.

k k k k k 600 604 602 602 After measuring the actual position of the template chuck at particular time t, the position control methodmay proceed to step Swhere a target template chuck position is generated for the same time t. The target template chuck position is the position that the template chuck should have been at according to the predetermined position trajectory at the time tthat the actual position was measured in step S. In other words, if the template chuck had followed the predetermined position trajectory perfectly, the actual position measured in step Sat time twould be the same as indicated in the predetermined position trajectory at the time t. However, this is typically not the case.

600 606 604 602 608 604 608 k k k k+1 k+1 k+1 The position control methodmay then proceed to step Swhere a position error of the template chuck at the time tis determined. The position error is the difference between the target position of the template chuck at time tdetermined in step Sand the actual position of the template chuck at the same time tmeasured in step S. After the position error is determined, the method may proceed to step Swhere a target position of the template chuck is determined for the next time t. As in step S, the target position of the template at time tdetermined in step Sis the position that the template chuck should be at according to the predetermined position trajectory at the time t.

k+1 k+1 k+1 608 610 606 610 610 612 118 602 118 After determining the target position of the template chuck at the time tin step S, the method may proceed to step Swhere a position correction amount is generated based on the position error determined in step Sand the target position of the template chuck at time tdetermined in step S. The position correction amount is how much the template chuck needs to be moved so that the position of the template chuck will more closely follow the predetermined position trajectory. Thus, once the correction amount is determined in step S, the method may proceed to step Swhere the template chuckis moved based on the correction amount. This is achieved by sending an instruction to the actuator acting upon the template chuck to move the template chuck toward the substrate. The instruction may be a specific desired position at the time tfor each of the actuators or a specific control effort that each of the actuators will supply. The instructions to the actuator may be generated using for example a PID type control system, a state-space control system, or some other control system that takes current and past information into account. The method then proceeds back to step Sto repeat the method so that any position error is continuously accounted for while the template chuck approaches the substrate. If position error is not continuously accounted for, the actual position of the template chuckwill not follow the predetermined position trajectory.

650 652 602 652 600 124 650 652 contact f k k 6 FIG.B The force control methodmay begin with stepwhere the actual position of the template chuck is measured in the same manner as step S. At the start of the method in stepthe template chuck has already moved toward the substrate following the position control methodand is now moving following a predetermined force trajectory. The timing of switching between the two control schemes is discussed below. The predetermined force trajectory is data indicating what the desired residual force imparted onto the template chuck by the one or more actuators should be at a particular relative time during an imprinting process. The residual force is the net force of the forces acted upon the template chuck by the one or more actuators and any counteracting forces imparted by one or more springs and/or flexures. The predetermined force trajectory is the residual force that has been experimentally determined to have good filing performance of the formable materialduring the contacting period Tand the filling period T. As soon as the template chuck begins to move toward the substrate to follow the predetermined force trajectory, the force control methodfeedback loop is implemented. Thus, the actual position of the template chuck measured in step Sis performed at a particular time t. In other words, each time the method ofis performed, the actual position of the template chuck is measured for a particular time t.

k k k k k 652 600 654 654 656 652 118 654 652 118 102 After measuring the actual position of the template chuck at particular time t(step S), the force control methodmay proceed to step Swhere the force being imparted by the actuator onto the template chuck is measured at the same time t. The actual force being imparted by the actuator may be measured by for example by measuring the control current, control voltage, output of a force sensor, or the instructed force supplied by the supplied by the controller to the one or more actuators. After measuring the force imparted to by the actuator in step S, the method may proceed to step Swhere the estimated residual force imparted by the actuator at the time tis determined. The estimated residual force is the net force applied onto the template chuck. The estimated residual force is determined from the measured actual positions of the template at the time t(S) and the measured force imparted on the template chuckat time t(S). The estimated residual force depends on the position of the template chuck determined in step Sbecause as the template chuckmoves closer the substratethe spring forces and flexure forces varies with the position of the template chuck relative to the bridge. The estimated residual force may be measured based on previously gathered calibration data and the sensed position. In an embodiment, there may be multiple residual forces (one for each actuator). The multiple residual forces may be generated using a MIMO (multiple input multiple output) calibration process. Thus, knowing the position of the template chuck correlates to the force imparted by the one or more flexures and springs and one can determine the residual force.

656 658 118 652 118 656 k k k k contact f After determining the estimated residual force (S), the method proceeds to step Swhere a target residual force is determined for the same time t. The target residual force is the net force that should have been imparted onto the template chuckaccording to the predetermined force trajectory at the time tthat the actual position was measured in step S. In other words, if the template chuckhad followed the predetermined force trajectory ideally, the estimated residual force determined in step Sat time twould be the same as indicated in the predetermined force trajectory at the time t. However, because of noise in the environment and positioning system and the desire to have sub-Newton force control during the contacting period Tand the filling period Tthis is typically not the case.

650 660 658 656 662 658 662 k k k k+1 k+1 k+1 k+1 The force control methodmay then proceed to step Swhere a residual force error on the template chuck at the time tis determined. The residual force error is the difference between the target residual force on the template chuck at time tdetermined in step Sand the estimated residual force on the template chuck at the same time tmeasured in step S. After the residual force error is determined, the method may proceed to step Swhere a target residual force on the template chuck is determined for the next moment in time t. The target residual force for the next moment in time tis obtained from the predetermined force trajectory. As in step S, the target residual force on the template at time tdetermined in step Sis the residual force that should be applied to the template chuck by the actuator in order to comply with the predetermined force trajectory at the time t.

k+1 k+1 k+1 662 664 660 662 664 666 664 666 652 After determining the target residual force on the template chuck at the time t(S), the method may proceed to step Swhere a force correction amount is determined based on the residual force error determined in step Sand the target residual force at time tdetermined in step S. The force correction amount is how much force the actuator needs to apply to the template chuck so that template chuck will more closely follow the predetermined force trajectory. The force correction amount may be a specific desired force to be supplied at the time tfor each of the actuators or a specific control effort that each of the actuators will supply. The instructions to the actuator may be generated using for example a PID type control system, a state-space control system, or some other control system that takes current and past information into account. Thus, once the force correction amount is determined in step S, the method may proceed to step Swhere an instruction is sent to the actuator to apply a force onto the template chuck based on the correction amount from step S. Upon receiving the instruction, the actuator will provide the force from step Swhich will move the template chuck toward the substrate. The method then proceeds back to step Sand the method is repeated so that any force error is continuously accounted for while the template chuck approaches the substrate. If residual force error is not continuously accounted for, the estimated residual force of the template chuck will not follow the predetermined residual force trajectory.

600 650 130 7 FIG.A FF As noted above, in the shaping/imprinting process, the template chuck movement is initially controlled according to the position control methodand then, at a predetermined moment in the shaping/imprinting process, control of the template movement switches to the force control method. More particularly, there is an ideal distance from the substrate where switching between the two types of control methods provides optimal shaping/imprinting results. The location where ideal switching occurs is referred herein as the target imprint plane (TIP). The TIP is a virtual plane located at a distance in the Z direction from the substrate. The TIP is parallel to an average plane of the substrate surfaceof the imprint field to be imprinted, when the substrate is held flat and does not change even if the template is tilted or otherwise non-parallel and the substrate is deformed by differential pressures applied by different zone of the substrate chuck. The target imprint plane can be experimentally determined. To determine the TIP, a series of testing imprints are performed. In each test imprint, a different location of the potential TIP (i.e., the Z dimension location where switching between position control and force control occurs) is implemented, with all other factors being kept the same. That is, the identical imprinting process is performed with the only difference being the location of the potential TIP. The results of the imprinting are examined to determine which potential TIP location provides satisfactory performance. The satisfactory performance may be determined by examining which has the best filling performance, minimal defects, uniform RLT, and throughput within an acceptable error. The tested TIP that provided the satisfactory performance is determined to be the actual TIP to be used. In the case of full fields, all future full field imprints of the same pattern, same imprinting process, and using the same imprinting system will have the same TIP. That is, for a full field, once the TIP is determined it can be applied to all full field imprinting using the same imprinting system for the same pattern and for the same process.shows a schematic sectional view of a swelled template as it approaches the TIP for a full field imprinting (TIPbeing the TIP for a full field).

112 130 The reference point for determining when a template chuck has reached the TIP is for example 5-10 μm between the shaping surfaceand the substrate surface. The reference point for determining when a template chuck has reached the TIP for a full field, a partial field, or a small partial field may be the average z position as measured by the three position encoders used to measure the position of the template adjusted to take into account variation in height of the substrate chuck. The reference point may also be a specific point on the template or the template chuck. The reference point may be the center of mass of the template chuck. The reference point may be the center of mass of the template chuck, and portions of shaping head that that move with the template chuck.

5 FIGS.D-E However, the TIP for a full field is not applicable to a partial field and small partial fields. This is primarily because for partial fields, and more particularly for small partial fields, the swelling of the template during imprinting is different for each unique partial field. Furthermore, when imprinting partial fields and small partial fields at the edge of the substrate, the substrate is modulated to curve the substrate (see). Thus, if the TIP for a full field is used when imprinting partial field or small partial fields, the imprinting performance is often not satisfactory.

7 FIG.B PF shows a schematic sectional view of a swelled template at is approaches the TIP for partial field or small partial field imprinting (TIPbeing the TIP for a partial field or small partial field).

While it is possible to determine the TIP for each unique partial field and small partial field, it is unduly burdensome and requires multiple experiments. Rather than experimentally determining the TIP for every partial field and small partial field, the TIP can be estimated based on the already determined TIP for a full field. The following formula (1) can be used to estimate the TIP for partial fields or small partial fields based on the known TIP for full fields.

FF TIPis the TIP for a full field, which is a first distance from the substrate; i,PF TIPis the TIP for a particular partial field or small partial field i, which is a second distance from the substrate; Sw is a swell ratio of the template; T,FF Pis the back pressure control value for a full field; i,T,PF Pis the back pressure control value for the particular partial field or small partial field i. In formula (1):

FF As discussed above, TIPis a known value (distance from the substrate) determined through prior experimentation and is constant for all full fields once determined in a particular imprinting system.

Sw is a property of the particular template and is determined experimentally. For a particular template, the template is loaded on the imprint head and different back pressures are applied to the template so that it bends toward the substrate. The distance between the maximum extended point of the template (generally at the center) and the substrate (or “swell”) is measured for each different applied backpressure. Enough measurements are taken so that a trendline can be fitted to the data, which is generally a linear fit. The slope of the fitted line is the swell ratio Sw of the particular template. The units for Sw is distance/pressure, e.g., μm/kPa.

T,FF T T Pis determined as discussed above with respect to control value P, and described in detail in the '074 application. “FF” refers specifically to a full field, but is otherwise the same control value as P.

i,T,PF i,T i,T Pis determined as discussed above with respect to control value P, and described in detail in the '074 application. “PF” refers specifically to a partial field or a small partial field, but is otherwise the same control value as P.

FF T,FF i,T,PF i,PF i,PF i,PF Using the above formula (1), with TIPbeing known, Sw being known, Pbeing known, and Pbeing known, it is possible to determine TIPfor each partial field or small partial field i. Notably, by using this formula, TIPis determined without the need to experimentally determine TIPfor each partial field or small partial field i.

i,T i,Tx i,Ty i,Sa i,Sb i,Sc i,PF i,PF 5 FIG.C 5 FIG.D In another example aspect, the formula (1) may be modified to account for template tilt control parameters (θ={θ, θ},, discussed above) and substrate pressures control parameters (P, P, and P,, discussed above). That is, the tilt of the template and the substrate pressures may also impact the desired TIP. Thus, the formula (1) can be modified such that TIPis additionally based on template tilt and substrate pressures or any other change to the template or substrate surface to cause a topographical change around the partial field.

300 300 302 306 302 304 802 304 600 8 FIG. 8 FIG. 6 FIG.A Returning to the shaping method,illustrates additional steps of the methodspanning steps Sto S. As shown in, after the formable material has been dispensed in step S, and prior to the contact step S, the method includes step Swhere the template chuck is moved toward substrate under position control of. That is, prior to contact step S, the template chuck movement follows the position control method.

8 FIG. 7 FIG.A 7 FIG.B 600 FF FF i,PF i,PF FF i,PF FF i,PF FF i,PF FF i,PF Next, as shown in, the template chuck continues to move toward the substrate under position control methoduntil the TIP is reached. In the case of a full field being imprinted, the TIP is notated as TIP, which as discussed above is the same location for every full field. As noted above, TIPis illustrated inand is predetermined distance from the substrate based on experimentation. In the case of a partial field or small partial field being imprinted, the TIP is notated as TIP, which as discussed above is the TIP determined for a particular partial field or small partial field. As noted above, TIPis illustrated inand is predetermined distance from the substrate using formula (1) and does not need to be determined from experimentation. The moment in the overall imprinting process that the TIP/TIPis reached may be based on timing or based on location information of the template chuck. That is, in the case of teaching the TIP/TIPbeing based on timing, the controller may be provided with instructions that at a certain predetermined time in the imprinting process, the template chuck will have reached the predetermined TIP/TIP. In the case of location information, the predetermined TIP/TIPwill have been reached when position sensor information informs the controller that the template chuck is at the proper location.

FF i,PF FF i,PF 806 600 650 804 806 806 804 6 FIG.A 6 FIG.B After reaching the TIP/TIPthe method may proceed to step Swhere the movement of the template chuck switches from the position control methodofto the force control methodof. Preferably, the switch occurs simultaneously or contemporaneously with the template chuck reaching the TIP/TIP. More preferably, the switch occurs simultaneously, i.e., such that step Sand step Soccurs at the same instant. In another aspect, the switch may occur contemporaneously, i.e., step Soccurs within several milliseconds of step S.

806 304 304 304 306 308 300 804 808 300 contact 3 FIG. 3 FIG. 3 8 FIGS.and After switching to force control in step S, forces are applied to the template chuck such that the template chuck continues to move toward the substrate under force control until the contact with the formable material is reached (S). The force control continues until the contact step Sis complete, i.e., at the end of T. Towards the end of the contact period, force control continues to apply force, although the template chuck may no longer be moving. After completing the contact step S, the method continues with steps in. That is, the method proceeds to steps S, S, etc., according to the methodof. Thus, as shown in, the additional steps Sto Sexist within the overall method.

300 300 8 FIG. FF i,PF All fields can be imprinted using the same methodincluding the additional steps of. That is, the same methodis applicable to full fields, partial fields, and small partial fields. The difference is that for all full fields the same TIPis used and the same control values are used, while for each unique partial field and small partial field a unique TIPand unique control values are used that are unique to the particular partial/small partial field.

300 600 650 FF i,PF TIP contact TIP IC TIP When performing the method, the control values discussed in the '074 application are implemented in the similar manner as discussed in the '693 patent, except that the moment that TIP/TIPis reached (t) just before Tbegins. That is, the moment tis reached is just before initial contact time (t), and the moment tis when the control switches from the position control methodto the force control method.

9 FIGS.A-G 9 FIGS.A-G 9 FIG.A IC TIP IC T T1 IC T2 IC T are timing diagrams illustrating how control conditions may vary over time before and after the initial contact time (t) in an exemplary embodiment of imprinting partial fields and small partial fields.also show the at the time that TIP is reached (t) relative to the initial contact time (t).is a timing diagram illustrating how the template back pressure (P) is adjusted to an initial template bowing pressure (P) prior to the initial contact time (t) and then adjusted to a gas release template bowing pressure (P) after the initial contact time (t). The template back pressure (P) is then adjusted until the template is flat relative to the substrate.

9 FIGS.B-C Sa Sb Se IC 308 308 are timing diagrams illustrating how the substrate back pressures (P, P, and P) are adjusted to bow out the substrate prior to the initial contact time (t) and then the pressure is adjusted prior to curing step Sso that the substrate and the template are parallel to each other during the curing step S.

9 FIG.D 108 124 300 308 IC is a timing diagram illustrating how the contact force that the templateapplies to the formable materialmay be adjusted during the shaping process. The contact force may increase after the initial contact time (t) and then be reduced to a final imprint force prior to start of the curing step S.

9 FIGS.E-F 108 102 308 T IC are timing diagrams illustrating how the templateand the substrateare oriented relative to each other. The template control angles (θ) may be increased prior to the initial contact time (t) and are then reduced until the template and substrate are parallel with each other during the curing step S.

9 FIG.G T IC 300 108 124 112 130 308 is a timing diagram illustrating how the template chuck position (z) is adjusted during a part of the shaping process. The distance between the template chuck and the substrate is reduced until the bowed out templatecomes into contact with the formable materialat the initial contact time (t). The position is then adjusted as the template, and substrate, become unbowed and parallel to each other until there is a small residual layer thickness of formable material between the shaping surfaceand the substrate surfaceduring the curing step S.

10 FIG. 6 FIG. 304 304 600 650 1002 304 1004 a a IC T T Sb Sa Sc T T IC is a flowchart illustrating more detailed steps performed during the contacting step Sfor partial fields and small partial fields in an exemplary embodiment. As noted above, prior to step S, the template chuck moves according to the position control methodofand switches to the force control methodupon reading the TIP (step S). The contacting step Smay include an initial control conditions setting step Sin which the control conditions are adjusted to an initial set of control conditions at a first time (t) prior to an initial contact time (t). The initial set of control conditions may include: a template back pressure (P) to an ICP template back pressure; the tip and tilt of the template (θ); first inner ring substrate pressure (P); outer ring substrate pressure (P); second inner ring substrate pressure (P); the template chuck position (z); etc. The tilts, the template chuck position (z), and pressures should be adjusted to the values which controls the ICP at the initial contact time (t) as discussed in the '693 patent.

a IC IC b T 112 124 118 1004 b After the first time (t) the template chuck position is adjusted until the shaping surfaceis brought into contact with the formable materialat the ICP at the initial contact time (t). After the initial contact time (t) and before a second time (t), the template chuckmay adjust the template back pressure (P) from an ICP template back pressure to a gas escape template back pressure in a back pressure adjustment step S. The gas escape template back pressure may be greater than the ICP template back pressure. The ICP template back pressure is chosen to ensure that initial contact happens correctly while the gas escape template back pressure is chosen to ensure that gas can escape as droplets of formable material spread underneath template as more of the template is brought into contact with the formable material.

b c c d 1004 1004 1004 1004 1004 1004 c d d c d c. Between the second time (t) and a third time (t), the tip and tilt of template is adjusted in a tilt adjustment step Suntil the template chuck is substantially parallel to the substrate chuck. After the tilt is adjusted, in a pressure adjustment step Sthe substrate chuck pressure and template chuck pressure are adjusted after the third time (t) and before the fourth time (t) until both the template and the substrate are no longer bowed out. In an alternative embodiment, the pressure adjustment step Sis performed at the same time as the tilt adjustment step S. In another alternative embodiment, the pressure adjustment step Sis performed before the tilt adjustment step S

IC a IC d T 1004 112 308 1004 e f 9 FIG.D At the initial contact time (t) and before the fourth time (t), during a force adjustment step S, the force that the shaping surfaceapplies to the formable material is adjusted until a final force is reached that will be applied during the curing step Sas illustrated in. After the initial contact time (t) and before the fourth time (t), during a template position adjustment step Sthe position of the template chuck (z) is adjusted relative to the substrate chuck until there is a set residual layer thickness of formable material between the shaping surface and the substrate surface.

Further modifications and alternative embodiments of various aspects will be apparent to those skilled in the art in view of this description. Accordingly, this description is to be construed as illustrative only. It is to be understood that the forms shown and described herein are to be taken as examples of embodiments. Elements and materials may be substituted for those illustrated and described herein, parts and processes may be reversed, and certain features may be utilized independently, all as would be apparent to one skilled in the art after having the benefit of this description.